Specifically but not exclusively the apparatus of the invention is useful for realising, by means of engraving, matrices on matrix-bearing cylinders, provided with at least one external peripheral part which is elastically deformable, used in decoration and glazing of ceramic tiles.
Particular reference is made to matrices engraved on smooth cylindrical surfaces made in silicone rubber, which are constituted by patterns composed of a plurality of microscopic cavities predisposed to house small quantities of glaze.
The cavities, usually distributed over all of the cylindrical surface, can be of various sizes and thus can contain various quantities of glaze. This possibility of variety has the aim of enabling various quantities of glaze to be transferred on to the tiles, in order to obtain a good half-tone quality thereon.
Flexographic cylinders are already well known wherein lasers are employed to engrave on the elastic surface. The most common alternative to the above is the photoengravure technique.
Engravure on a flexographic cylinder, including techniques employing the use of a laser, is effected by removing material from the cylinder surface such as to leave a relief pattern on said surface, which protruding pattern therefore constitutes the active surfaces for the transfer of the ink or the glaze on the support to be printed on.
The above-illustrated prior art therefore engraves on the material, removing it, thus constructing a pattern to be printed or reproduced. It is therefore unsuitable for the reticulation technique necessary for the creation of half-tones.